Apparatus for converting a wheeled vehicle to a tracked vehicle

ABSTRACT

The invention relates to a self-propelled, wheeled irrigation vehicles ( 10 ) that may be converted into a multi-track self-propelled irrigation vehicle ( 60 ) using one or more track assemblies ( 62 ). Each track assembly ( 62 ) includes a carriage ( 70 ) with frames ( 92, 94 ) that support a plurality of pairs of idler wheels ( 74, 76 ), and pairs of bogey wheels ( 80, 82, 84 ). A portion of one of the frames ( 94 ) is telescopically received within a portion of the other frame ( 92 ), so that the frames ( 92, 94 ) may move relative to each other in a linear fashion. A tensioning apparatus ( 212 ) is connected to the frames ( 92, 94 ) so that the frames are adjustable relative to each other. Each carriage ( 70 ) also includes a hub support frame ( 90 ) that is connected to one of the frames ( 92 ) in an offset manner. The hub support frame ( 90 ) includes an aperture ( 132 ) that rotatably receives a spindle ( 262 ) of an adaptor ( 258 ). The adaptor ( 258 ) includes a peripheral flange ( 264 ) to which a segmented sprocket ( 86 ) may be connected, and a ring extension ( 268 ) that is able to be connected to an existing wheel hub of an irrigation vehicle whose drive wheel has been removed. A flexible endless track ( 88 ) is entrained about the wheels ( 74, 76, 80, 82, 84 ) and the sprocket ( 86 ). The track assembly ( 62 ) may be provided with one or more cleats ( 278 ) that are removably connected to the flexible, endless track ( 88 ), and which include a ground engaging member ( 281 ) that serves to increase the traction of the endless track ( 88 ).

RELATED APPLICATIONS

This application is a National Stage entry under 35 U.S.C. §371 ofPCT/US2008/075442, filed on Sep. 5, 2008, which claims priority to U.S.provisional application Ser. No. 60/970,764 filed on Sep. 7, 2007.

FIELD OF THE INVENTION

The present invention relates to an apparatus for converting a wheeledvehicle to a tracked vehicle. More specifically, the present inventionrelates to track systems that may be used to convert a self-propelledtire or wheel supported irrigation vehicle to self-propelled multi-trackirrigation systems.

BACKGROUND OF THE DISCLOSURE

Self-propelled wheeled irrigation systems are old and well known in theart. Such systems were originally designed to provide irrigation forlarge parcels of land, particularly farmland. Such irrigation systemsmost often take the form of a central pivot irrigation system or alinear move irrigation system. In both types of systems, an elevatedmain water conduit or pipe is movably supported by one or more towerstructures that include self-propelled tires or support wheels. Often,these irrigation vehicles are used in conditions where the surface uponwhich they traverse is not capable of supporting the weight of theself-propelled tire or wheel supported irrigation systems and they canbecome mired and/or lose traction. And, because the irrigation vehiclestravel along prescribed paths, the tires or drive wheels tend to formruts. This is exacerbated when portions of the path become wet andwaterlogged. In such situations, the tires or drive wheels loosetraction and one or more towers of the irrigation vehicle can lag behindthe general motion of the vehicle, which can cause undue stress andstrain on the towers and the main elevated water conduit or pipe, andcould lead to failure. In some situations, a drive wheel section canbecome stuck, which again, can lead to failure of the vehicle. Unduestress and strain can also be result of tires or support wheels thathave gone flat or lost significant amounts of air pressure, which canalso cause one or more towers of the irrigation vehicle to lag behindthe general motion of the vehicle. Therefore, tires or support wheelsmust be periodically checked to insure that they are properly inflatedand that they have sufficient tread to operate as designed.

It will be appreciated from the foregoing, therefore, that prior artself-propelled wheeled irrigation vehicles present problems that are inneed of solutions and there is a need for a self-propelled irrigationvehicle that is able to be used in conditions that would not otherwisebe possible.

SUMMARY OF THE INVENTION

Generally, the present invention is an apparatus for converting thewheeled irrigation vehicle to a tracked vehicle. The apparatus forconverting a wheeled vehicle to a tracked vehicle includes a tracksystem that is configured and arranged to be attached to existing wheelhubs of the vehicle. Preferably the vehicle is a self-propelled,center-pivot, linear-move wheeled irrigation system, or the like.

A preferred embodiment of the track system that includes carriage havinga hub support frame, a first wheel support frame and a second wheelsupport fame to which a sprocket, bogey wheels and idler wheels arerotatably mounted. A flexible, endless track is installed about thecarriage so that its inner surface contacts the wheels and the sprocket,which drivingly engages a flexible, endless track.

The sprocket comprises a plurality of sprocket segments that areattached to an adaptor that is configured and arranged to be removablyattached to an existing wheel hub flange of a wheeled irrigationvehicle. Preferably, the sprocket is a split sprocket. The adaptorincludes a spindle that is rotatably attached to a hub, with the hubattached to spaced apart, generally parallel plates of a supportstructure. The hub support structure is attached to a first wheelsupport structure onto which a plurality of idler and bogey wheels arerotatably mounted. Preferably, the hub support frame is attached to thefirst wheel support structure in an offset manner to enable the sprocketto be positioned in alignment with the longitudinal axis of the firstsupport structure. The carriage also includes a second wheel supportframe that includes a plurality of idler wheels, and which is adjustablyconnected to the first wheel support frame such that the peripherydefined by the sprocket, the idler and bogey wheels can be varied andthe carriage is able to provide the optimal operational tension for theflexible, endless track.

The wheelbase of the carriage is preferably adjustable to facilitateinstallation and/or removal of the track and to maintain adequatetensioning as the flexible track ages. As explained above, the first andsecond wheel support frames are operatively connected to each other sothat they can move relative to each other in a constrained manner.Preferably, the first and second wheeled frames are connected to eachother so that they are able to change the wheelbase of the carriage andthus adjust the tension under which the flexible track operates. Morepreferably, the first and second wheel support frames are telescopinglyconnected to each other. The carriage also includes a tensioningapparatus that is operatively connected to the first and second wheelsupport frames. The tensioning apparatus includes an expandable andretractable force exerting member such as a grease cylinder, hydrauliccylinder or the like. In use, the tensioning apparatus urges the firstand second wheel support frames away from each other along the generallongitudinal axis of the carriage.

The adaptor, to which the sprocket segments are attached, also includesa ring extension that has a plurality of apertures that are configuredand arranged to be aligned with bolt holes in the drive wheel flange ofan existing wheeled irrigation vehicle. As will be understood, theapertures in the ring extension may be customized to enable the adaptorto be attached to differently configured wheel hubs.

In certain conditions, it may be desirable to increase the tractioncharacteristics of the track assembly. This can be accomplished byproviding the assembly with endless tracks having different treaddesigns and dimensions. However, replacement or substitute endlesstracks are expensive and relatively time consuming to install. Moreover,the use of such replacement or substitute tracks is often transitory,and the need for such specialized or ground specific tracks is soonpast. A preferred alternative to track replacement or substitution is toprovide an endless track with one or more removably connectable cleats.Each cleat has a ground engaging member that is configured to increasethe traction characteristics of the endless track to which it isconnected. Each cleat also includes one or more attachment members thatallow the cleat to be operatively connected to the track. As will beappreciated, an endless track may be provided with one or more cleats.

An object of the present invention is to provide a track assembly thatcan be used to convert a wheeled vehicle into a tracked vehicle,preferably a self-propelled, tracked irrigation vehicle.

Another object of the present invention is to provide a track assemblywith a simplified track tensioning mechanism.

Yet another object of the present invention is to increase the tractionof a track assembly without having to replace the endless track.

Additional advantages and features of the invention will be set forth inpart in the description which follows, and in part, will become apparentto those skilled in the art upon examination of the following or may belearned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of a known, self-propelled prior artirrigation vehicle of the type having a main elevated water pipe orconduit that is supported by one or more towers, with each towerincluding a plurality of powered, support tires;

FIG. 2 is a side elevational view taken from one end of FIG. 1;

FIG. 3 is a front elevational view taken from one end of FIG. 2;

FIG. 4 illustrates the prior art irrigation vehicle of FIGS. 1-3 inwhich the powered, support tires of a tower have been removed andreplaced with track assembly units of the present invention;

FIG. 5 is a perspective view of one of the track assembly units of FIG.4 in which the track assembly unit has been rotated to present anon-attachment or outboard side, the view taken from a point above andto the right of the track assembly unit;

FIG. 6 is an elevational view of outboard side of the track assemblyunit of FIG. 5;

FIG. 7 is a cross-sectional, elevational view of the track assembly unitof FIG. 5,

FIG. 8 is an exploded, perspective view of the track assembly unit ofFIG. 5, taken from a point in front of, above and to the right of thetrack assembly;

FIG. 9 is a top plan view of the first wheel support frame and the hubsupport frame, which is attached to the outboard side of the first wheelsupport frame, and which is offset from the vertical plane of the firstwheel support frame;

FIG. 10 is an outboard side elevational view of FIG. 9;

FIG. 11 is an inboard side elevational view of FIG. 9;

FIG. 12 is a partially exploded, perspective view of the hub supportframe and the first and second wheel support frames of the carriageframe of the present invention, the view taken from a point behind,above and to the left;

FIG. 13 is a side elevational view of a sprocket segment of the presentinvention;

FIG. 14 is a perspective view of a sprocket segment of the presentinvention;

FIG. 15 is a perspective view of an adaptor of the present invention;

FIG. 16 is a cross-sectional view of the adaptor of FIG. 15;

FIG. 17 is a front plan view of the adaptor of FIG. 15;

FIG. 18 is perspective view of an attachable cleat for use with aflexible track;

FIG. 19 is an elevational view of a cleat of the present invention as itmay be attached to a flexible track;

FIG. 20 is a perspective view of an alternative embodiment of aflexible, endless track, the view taken from a point in front of and tothe right of the track;

FIG. 21 is a perspective view of the endless, flexible track of FIG. 20,taken from a point in front of and to the left of the track; and,

FIG. 22 is a bottom plan view of the endless, flexible track of FIG. 20.

DETAILED DESCRIPTION

Referring initially to FIG. 1, a portion of a known prior artself-propelled irrigation vehicle 10 is shown. The typical prior artvehicle 10 generally comprises individual span units 12 that have afluid conduit 14, with the fluid conduit supported by a truss assembly16. The truss assembly 16 is, in turn, supported between movable supportstructures 20 that propel the individual span units 12 of the irrigationsystem.

Referring to FIG. 2, each prior art movable support structure 20 usuallycomprises a frame 22 having a main horizontal beam 24 and inclinedbraces 26, 28 that extend between the horizontal beam 24 and the trussassembly 16. Each movable support structure 20 has a power or motivesource 30 with an optional brake 31, and a transmission 34 that areattached to the main beam 24 by a bracket 32. The support structure 20also includes drive shafts 36, 37 that are connected to the power ormotive source 30 via the transmission 34, and which terminate inuniversal joints 50, 51. The universal joints 50, 51 are, in turn,connected to input shafts 52, 53 connected to gear boxes 54, 55 that arereceived by mounting brackets 42, 43, respectively. The mountingbrackets 42, 43 are attached at opposite ends of the main beam 24, andextend downwardly therefrom. Referring to FIG. 3, each gear box mountingbracket 42, 43 is generally u-shaped and includes a lateral wall 44 witha center aperture and circumferential gear box attachment apertures, andopposing inboard and outboard end walls 46, 48. When attached to a mainbeam 24, the lateral wall 44 is generally parallel to the main beam 24and the end walls 46, 48 are generally transverse to the longitudinalaxis of the main beam 24. Preferably, outboard end wall 46 is configuredso that it is able to cover the end of the main beam 24, while theinboard end wall includes a cutout that corresponds to the bottomsurface of the main beam 24. Each gear box 54, 55 is connected to oneside of the lateral wall 44 of a respective mounting bracket 42, 43 suchthat its output section (not shown) is able to extend through thelateral wall and through a cover assembly 56 that is attached to theother side of the lateral wall. As can be seen in FIG. 3, the outputsection of each gear box 54, 55 is ultimately connected to a hub with aflange 58 that may include fastening elements 59. A tire or supportwheel 38, 40 of the self-propelled irrigation vehicle 10 is attached andsecured to each flange 58 with fastening elements 59 and lug nuts (notshown) in a conventional manner.

Briefly, FIG. 4 illustrates an irrigation vehicle 60 combined with trackassemblies 62 of the present invention. Generally, each track assembly62 includes a carriage 70 that supports a plurality of idler wheels 74,76, internally positioned bogey wheels 80, 82, 84, a drive sprocket 86and a flexible, endless track 88. As can be seen, each pneumatic drivewheel or tire has been removed and replaced by one track assembly orunit 62. Advantageously, each track unit 62 has a connection point withan elevation or height “D” that permits the irrigation vehicle 60 tooperate with substantially the same ground clearance that is providedwith wheeled versions. As is further discussed below, each track unit 62preferably has a maximum height “H” of around 38 inches (96 cm) and awheelbase “L” that is defined by the distance between the rotationalaxes of idler wheels 74, 76, which are attached to shafts 72.Preferably, the wheelbase “L” is around 53 inches (134 cm). However, aswill be apparent, the length of the wheelbase “L” can preferably bevaried by about plus or minus 8 inches (20 cm). As will be appreciated,this allows the carriage 70 to accommodate changes to the track 88 as itages. It also allows the carriage to accommodate similar endless tracksthat may be fabricated by manufactures other than the originalmanufacturer, or endless tracks that may be different or which may havedifferent applications than the original flexible, endless tracks. Withthe present invention, the track 88 has a preferred width “W” is around15 inches (38 cm) and an inner periphery or pitch length of around 166inches (421 cm).

FIGS. 5-8 illustrate, in greater detail, a track assembly or unit 62 ofthe present invention in isolation. FIGS. 5 and 6 are outboard viewsthat show a track assembly 62 unit with its carriage 70 that supportspaired idler wheels 74, 76 located at either end, pairs of bogey wheels80, 82, 84 located between the idler wheels, and a sprocket 86.Preferably, the sprocket 86 is a split sprocket and includes first andsecond sections 230, 232. Note, in FIG. 7, that the carriage 70 has au-shaped recess having a radius that is larger than the radius of thesprocket 86. This allows the sprocket 86 and its fastening elements 252to be easily accessed from a transverse direction, relative to the trackassembly 62. As will be understood, this arrangement facilitatesrelatively unhindered servicing, attachment and removal of the sprocket86 to an adaptor 258, because the sprocket parts and fastening elementsare not covered or obscured by portions of the carriage 70. Moreover, itwill be appreciated that the sprocket 86 may be connected to the adaptor258, the sprocket and adaptor connected to a wheel hub of an irrigationvehicle, and then the sprocket and adaptor connected to a carriage of atrack assembly unit 62 (with the carriage being mounted on to a spindle262 that extends transversely from the adaptor 258). Conversely, thesprocket 86 may be connected to the adaptor 258, the sprocket andadaptor connected to a carriage of a track assembly unit 62, and thetrack assembly connected to a wheel hub of an irrigation vehicle. Itwill also be understood that when a track assembly unit 62 is connectedto a wheel flange of an irrigation vehicle, the track assembly unit willbe able to tilt or rotate without being constrained. This featureenables the track assembly unit to have the ability to surmountobstacles or barriers. It also enables the track assembly unit tomaintain maximum contact with the ground while the track assembly unittraverses undulating surfaces such as swales. Preferably the trackassembly unit has a normal operational range of rotation that is aboutplus or minus 45 degrees from the horizon. As will be disclosed below,for steep grades, a user of the track assembly unit may provide the unitwith optional cleats. FIGS. 5 and 8 are perspective outboard views ofthe track unit 62 that depict the hub support frame 90, which islaterally offset from the wheel support frames 92, 94 of the carriage70. FIG. 6 is a side elevational view of FIG. 5 and it shows how plates234 of each sprocket segment 230, 232 are connected to the adaptor 258.

More specifically, the carriage frame 70 of the present invention can bedivided, generally, into three components. The first component is a hubsupport frame 90. The second component is a first wheel support frame92, and the third component is a second wheel support frame 94. Withparticular attention to FIGS. 9-12, the hub support frame 90 generallycomprises plurality of plates 100, 110 that are connected to each otherto form a box-like structure having parallel, spaced-apart,arcuately-shaped notches or cradles 102, 118 that are configured toreceive and support a hub 128 having an exterior surface 130 and aninterior surface 132. As can be seen, the hub 128 is in the form of asleeve, with the interior surface 132 configured and arranged torotatably engage and support a spindle 262 of an adaptor 258, discussedbelow. The hub support frame 90 comprises a generally verticallyoriented outboard plate 100, a generally vertically oriented inboardplate 110, and a plurality of top plates 124, 126 that connect theoutboard and inboard plates together to form a partial enclosure.Preferably the plates 100, 110, 124 and 126 are provided with tabs “T”and/or slots “S” and notches “N”, which facilitate dry assembly of thepartial enclosure prior to final weld-up. The generally verticallyoriented outboard plate 100 is generally triangularly shaped andincludes a truncated apex with a notch 102, two side extensions 104, 106and a bottom extension 108. The extensions 104, 106, 108, which arepreferably generally rectangular and have substantially the same width,are bent inwardly approximately ninety degrees relative to the plane ofthe outboard plate 100 to form the side and bottom walls of the hubsupport frame 90. The generally vertically oriented inboard plate 110 isgenerally arcuately-shaped and includes outer and inner circumferences112, 114 that have inwardly directed notches 116, 118 and radial edges120, 122 that extend between the outer and inner circumferences. Notethat the outer circumference 112 is configured to substantially matchthe curvature of the side edge of top plate 174, to which it isultimately connected. As explained above, the notch or cradle 118 isconfigured to cooperate with the notch or cradle 102 of the outboardplate 100 to receive and support the hub 128. The notch or cutout 116located on the outer circumference 112 of the inner plate 110 isconfigured and arranged to provide a relief or clearance for a bogeywheel positioned therebelow. The upper edges 105, 103, 120, 122 of theoutboard plate 100 and the inboard plate 110, respectively, areconnected to each other by rectangularly shaped top plates 124, 126. Asbest depicted in FIG. 12, a portion of the bottom extension 108 isprovided with a generally rectangularly-shaped cutout 109 that isconfigured to provide clearance for a bogey wheel positioned therebelow.The edge portions on either side of the cutout 109 of the bottomextension 108 of the outboard plate 100 are connected to the inboardplate 110. As can be appreciated, this produces a rigid, lightweightstructure that is able to support the hub 128. It will be understoodthat the components of the hub support frame 90 may be provided withtabs “T” and slots “S” and/or tabs “T” and cutouts or notches “N” thatfacilitate assembly and ensure that the components will be correctlypositioned prior to final assembly. An important feature of the hubsupport frame 90 is that it is offset relative to the first and secondwheel support frames 92, 94. As will be appreciated, this offsetpositions the sprocket 86 so that it is in alignment with the idlerwheels 74, 76, the bogey wheels 80, 82, 84 and the endless track 88. Itwill also be appreciated that the hub support frame 90 protects thelower, outwardly facing portion of the sprocket 86 from dirt and debrisor other extraneous matter that might otherwise compromise normaloperation of the track assembly 62.

With particular attention to FIGS. 9-12, the first wheel support frame92 generally comprises plurality of plates that are connected to eachother to form a substantially enclosed, box-like structure having arecess that is configured to accommodate the drive sprocket 86 so thatit may freely rotate and be easily accessed. More specifically, thewheel support frame 92 comprises a generally vertically orientedoutboard plate 140, a generally vertically oriented inboard plate 158and a plurality of top, bottom, side and intermediate plates 174, 160,164, 166, 162, respectively, that connect the outboard and inboardplates 140, 158 together in a generally parallel relation. In preferredembodiments, the vertically oriented outboard plate 140, to which thehub support frame 90 is attached, includes a generally linear bottomedge 142 having one end that terminates in an upwardly angled portion144, an intermediate section 146 that is generally parallel with thebottom edge 142, and an upwardly facing, generally u-shaped section 148that extends from the intermediate section 146. The intermediate section146 of the outboard plate 140 is provided with a plurality of apertures150, 178 that are configured and arranged to receive shafts 78, 72 uponwhich the pairs of bogey 80, 82, 84 and idler wheels 74, 76 arerotatably mounted. In addition, one end of the intermediate section 146has an upper edge 152 that cooperates with the upwardly angled portion144 of the bottom edge 142 and the inboard and outboard plates 158, 140to form an angled first arm 154, while the other end of the intermediatesection 146 has an upper edge 156 that is in linear alignment with thebottom edge 142 of the outboard plate 140 and the longitudinal axis ofthe first wheel support frame 92. The generally vertically orientedinboard plate 158 is similarly constructed and arranged.

The generally vertically oriented inboard and outboard plates 158, 140are connected to each other by a series of plates 174, 160, 164, 166,and 162. More specifically, the vertical inboard and outboard plates158, 140 are preferably connected to each other by an angled bottomplate 160 (with angled end 161 and free end 165), an angled intermediateplate 162 (with angled end 167 and free end 169), angled side plates164, 166, a cap 170, and an arcuately shaped top plate or saddle 174that forms the recess for the drive sprocket 86. As with the previouslydescribed components, the plates 140, 158, 160, 164, 166, the cap 170and the top plate 174 are preferably provided with tabs “T”, slots “S”,and/or notches “N”, which facilitate assembly and ensure that thecomponents will be correctly positioned prior to final assembly. Notethat the sides of the intermediate plate 162 include a plurality of tabs“T” that are configured to be received in slots “S” in the inboard andoutboard plates 158, 140. Spaced in between the tab slots “S” areelongated plug weld slots 172 that are filled with weld material duringfinal assembly of the first wheel support frame 92. The top plate orsaddle 174, which is located above the intermediate plate 162 and theplug weld slots 172, preferably includes one or more notches or cutouts175 that provide relief or clearance for a pair of bogey wheels 82positioned on either side of the support frame 92. Note that one of thesegments of the angled side plate 166 is provided with an aperture 168through which a fastening element 220 for a tensioning apparatus 212 maybe accessed, with the fastening element 220 received in a transverselyoriented, apertured flange 159, and attachable to a threaded aperture163 located on intermediate plate 162. As will be understood, theoutboard, inboard, bottom and intermediate plates 140, 158, 160, 162located at the free end 167 of the wheel support frame 92 form a tunnelor conduit 176 that is configured and arranged to telescopically receivean end of the second wheel support frame 94. Preferably, the tunnel orconduit 176 has a polygonally shaped cross-section. More preferably, thetunnel or conduit 176 has a substantially square cross-section.

With particular attention to FIGS. 7, 8 and 12, the second wheel supportframe 94 generally comprises plurality of plates 180, 194, 196, 198,202, and a 200 that are connected to each other to form a box-likestructure having an angled arm 190 that is configured to receive a shaft72 for one set of the idler wheels 76. More specifically, the secondwheel support frame 94 comprises a generally vertically orientedoutboard plate 180, a generally vertically oriented inboard plate 194, acap 200 and plurality of top, bottom and end plates 198, 196, 202 thatconnect the generally vertically oriented outboard and inboard plates180, 194 together in a generally parallel relation. The preferredoutboard plate 180 is generally L-shaped and includes a generally linearbottom edge 182 that terminates in an upwardly angled portion 184, and agenerally linear top edge 186 that also terminates in an upwardly angledportion 188 to form an angled second arm 190. The outboard plate 180 isprovided with an aperture 192 that is configured and arranged to receivea shaft 72 upon which the idler wheel pair 76 is mounted. The inboardplate 194 is similarly constructed and arranged. The outboard andinboard plates 180, 194 are connected to each other by a cap 200 andseries of plates 196, 198, 202. More specifically, the outboard andinboard plates 180, 194 are connected to each other by an angled bottomplate 196, an angled top plate 198, a cap 200 and an end plate 202.

Preferably, the plates of the wheel support frame 94 are provided withcorresponding tabs “T” and notches “N” or tabs “T” and slots “S” (see,for example, end tab “T” located adjacent the end 201 of top plate 198and notch “N” of end plate 202; and side tabs “T” of top plate 198 thatfit into slots “S” of plates 194, 180). The tabs “T” and notches “N” orslots “S” allow the components of the support frame 94 to be assembledtogether and welded without the need for specialized jigs or fixtures.

In addition, the second wheel support frame 94 is provided with agenerally L-shaped bracket 204 that has a top surface 206, an engagementsurface 208 and an aperture 210 that is located in the engagementsurface 208, and which is configured and arranged to be operativelyconnected to a portion of the tensioning mechanism or apparatus 212.Preferably, the bracket 204 is connected to an angled end 199 of the topplate 198 of the wheel support frame 94, so that the center axis of theaperture 210 is generally parallel to the longitudinal axis of thesecond wheel support frame 94. As with the other components of thesupport frame 94, the bracket 204 and the top plate 198 are providedwith tabs “T” and slots “S” that engage each other to facilitateassembly. The second wheel support frame 94 is preferably configured tobe telescopically received within the tunnel structure 176 defined bythe outboard 140, inboard 158, bottom 160 and intermediate plates 162 ofthe first wheel support frame 92. As will be appreciated, embodiments ofthe invention are not limited to two wheel support frames and that theangled first arm portion 154 of the first wheeled frame 92 may bereplaced with a third wheeled frame (not shown) similar to the secondwheeled frame 94 without departing from the spirit and scope of theinvention.

Although it is possible to use a unitary sprocket, a split sprocket 86having first and second segments 230, 232, is preferred. As depicted inFIGS. 13 and 14, the sprocket 86 comprises two sprocket segments 230,232 that, when attached to an adaptor 258, form one sprocket 86 (seealso, FIGS. 7 and 8). Each sprocket segment 230, 232 comprises anarcuately shaped plate 234 having inner and outer circumferences 236,238. A plurality of teeth or bars 240 is evenly spaced about the outercircumference 238 in a transverse orientation and the ends of the teethor bars 240 are connected by side walls or rims 244, 246. The teeth 240and side walls 244, 246 define openings or gaps 242 therebetween, withthe gaps 242 configured to receive and engage inwardly extendingprojections 336 of a flexible track 88 (see, FIG. 8). The plate 234 alsoincludes a plurality of apertures 248 spaced evenly about and adjacentto the inner circumference 236, with the apertures 248 configured to bealigned with apertures 266 in a flange 264 that extends from the body260 of the adaptor 258, and secured thereto with a plurality offastening elements 252 (see, for example FIGS. 7 and 8). Additionally,the preferred plate 234 also includes a plurality of larger apertures250 that serve to reduce the weight of the plate 234. Preferably, thesprocket segments 230, 232 are formed by casting.

The adaptor 258 is used to connect each track unit 62 to the wheelflange 58 of an irrigation vehicle 10, whose wheel or tire has beenremoved. As shown in FIGS. 15-17, the adaptor 258 has a body 260 with aspindle 262, a flange 264 with apertures 266, and a ring extension 268.More specifically, the spindle 262 is configured and arranged to berotatably mounted within the spindle receiving aperture 132 of the hub128 of the hub support frame 90 (see, FIG. 8). The flange 264, which islocated at the periphery of the adaptor 258, is provided with aplurality of apertures 266 that are configured and arranged to bealigned with apertures 248 in the sprocket 86 and secured thereto withfastening elements 252 (see also, FIG. 8). The ring extension 268extends away from the body 260 of the adaptor 258 in a directionopposite from that of spindle 262. As depicted, the ring extension 268is generally circular and is provided with a plurality of wells 270, thebottoms of which have apertures 272 that are configured to be alignedwith apertures in the wheel flange 58 of the irrigation vehicle 10 andsecured thereto with fastening elements 274.

In order to maintain proper tension on the endless track 88 and toassist in its installation and removal, a tensioning apparatus 212 isprovided. Preferably, the tensioning apparatus 212 is operativelysecured to the first wheel support frame 92 and the second wheel supportframe 94. With particular attention to FIGS. 7, 8, and 12, thetensioning apparatus 212 is generally parallel to the longitudinal axesof the first wheel support and second wheel support frames 92, 94.Preferably, the tensioning apparatus 212 comprises a piston 214 that istelescopically connected to a cylindrical housing 216, with the pistonand housing of the tensioning apparatus 212 linearly extendable underpressure exerted from a non-compressible material such as hydraulicfluid or grease. As shown in FIG. 7, the tensioning apparatus 212 isarranged so that a pin or stub 222 at the free end of the housing 216 isinsertably received in the aperture 210 of bracket 204 and securedthereto by a fastener, such as a circlip. At the other end, a pineyemount 218 located at the free end of piston 214 is connected to thefirst wheel support frame 92 by a threaded fastening element 220. Asshown, the pineye mount 218 is bounded by and vertically aligned with atransversely oriented, apertured flange 159 and a threaded aperture 163that is located on intermediate plate 162. The fastener 220 is insertedthrough the aperture of flange 159, through the pineye mount 218 andinto threaded aperture 163. As shown, the transverse flange 159 isattached to the vertically oriented outboard and inboard plates 140, 158at a location located above intermediate plate 162. This positions thetensioning apparatus 212 so that it is substantially parallel to thelongitudinal axes of the first and second wheel support frames 92, 94.Note that fastening element 220 is accessible through aperture 168located in side plate 166. Note also that when the tensioning apparatusis installed, a portion of the tensioning apparatus will be protectivelypositioned within the interior of the first support wheel frame 92.Alternatively, the pineye mount 218 may be rotated 90 degrees so thatthe connection points to the first wheel support frame 92 will be at thevertically oriented inboard and outboard plates 140, 158. The wheelbase“L”, as defined by the idler wheel shafts 72, can be varied as the freeend of the second wheel support frame 94 moves within the tunnel orconduit 176 formed in the first wheel support frame 92. The amount ofmovement depends upon the force exerted by the tensioning apparatus 212,which can be adjusted via a grease fitting 224. This allows the trackassembly 62 to compensate for changes in the track 88 due to wear, tearand age. It also allows the track assembly 62 to accommodate similarendless tracks that may be fabricated by manufactures other than theoriginal manufacturer, or endless tracks that may be different or whichmay have different applications than the original flexible, endlesstracks. Preferably, the tensioning apparatus 212 is a grease cylinder.It will be understood, however, that other tensioning mechanisms may beused without departing from the spirit and scope of the invention. Forexample, threaded linear actuators, pneumatic actuators, springelements, or combinations thereof.

Generally, assembly of the carriage frame is facilitated by the use oftabs “T”, which fit into slots “S” or notches “N” in correspondingparts. As adjacent parts are fitted together using the tabs “T” andslots “S” and/or notches “N”, the parts are tack welded to each other.Then, after the carriage frame has been further assembled, the parts arefully welded together.

In certain instances, when a track assembly 62 becomes mired or facesobstructions such as unusually large mounds of soil, one or moretraction cleats 278 can be removably attached to the flexible, endlesstrack 88. With particular attention to FIGS. 7, 18 and 19 it will beappreciated, that a portion of each cleat 278 will project beyond theground contacting portion of the outer or exterior surface 89 a of thetrack 88 to enable the track to better engage the surface over which ittravels. Once the track 88 has cleared the offending area orobstruction, the cleat or cleats 278 can be removed. Preferably, eachcleat 278 comprises a body 280 with a ground engaging member 281 thatincludes two working surfaces that comprise elongated, generallyrectangularly-shaped plates 282, 284 with each plate 282, 284 havingfirst and second elongated edges 286 and 288, 290 and 292, and first andsecond side edges 287 and 289, 291 and 293, respectively. The plates282, 284 are connected to each other along their second elongated edges288, 292 forming an apex and positioning their respective firstelongated edges 286, 290 so that they diverge away from each other. Apreferred range of angles formed by plates 282, 284 is around 10-60degrees. It will be understood that the ground engaging member 281 isnot limited to two plates. Other configurations are possible withoutdeparting from the spirit and scope of the invention. For example, theground engaging member 281 may have an inverted T-shaped cross-section,or a somewhat rounded cross-section (not shown). In addition, it isenvisioned that the ground engaging member 281 could comprise aplurality of separate ground engaging members mounted on the body of thecleat (not shown).

Each cleat 278 further comprises first and second attachment members300, 310 are connected to the first elongated edges 286, 290 of therespective plates 282, 284. Preferably, each attachment member 300, 310is generally J-shaped or U-shaped and includes a generally elongatedfirst section 302, 312 that extends along the edge of a respective plate282, 284, a second section 304, 314 that is generally perpendicular to arespective first section 302, 312, and a third section 306, 316 that isgenerally perpendicular to a respective second section 304, 314 andgenerally parallel to a respective first section 302, 312. The first andsecond attachment members 300, 310 are attached to the first and secondplates 282, 284 so that the respective second and third sections 304 and314, 306 and 316 are adjacent the first end 294 of the body 280 of thecleat 278. Each cleat 278 further comprises a third attachment member320 is removably connected to the second end 296 of the body 280 of thecleat 278. As shown, the third attachment member 320 includes a sidewall 322 having an aperture 324 and an extension 326 that is generallyperpendicular to the side wall 322, and which, like the third sections306, 316 of the first and second attachment members 300, 310, is spacedfrom the edges 286, 292 of plates 282, 284. In use, the third sections306, 316 of the first and second attachment members 300, 310 and theextension 326 of the third attachment member are in a confrontingrelation. The third attachment member 320 is removably connected to thesecond end 296 of the cleat 278 by way of a fastening element 330.Preferably, the fastening element 330 is a threaded fastener thatextends through the aperture 324 in the side wall 322 and engages athreaded aperture 298 of element 297, which is attached to the cleatbody 280.

Attachment of a cleat 278 of the present invention onto a flexibleendless track 88 can be accomplished by first removing the thirdattachment member 320, if it is attached to the cleat body 280. Then,making sure that the portion of the track 88 to which the cleat 278 willbe attached is relatively free of dirt and mud, the cleat 278 ispositioned so that the first and second attachment members 300, 310 arealigned with parallel, transverse channels or grooves 332 that areformed between lands 334 on the outer or exterior surface 89 a of theflexible track 88. As will be appreciated, the first sections 302, 312of the first and second attachment members 300, 310 are configured andarranged to be positioned within the parallel channels or grooves 332 ofthe track 88 as the cleat 278 is attached to the track. When the cleat278 is attached to the track 88, the third sections 306, 316 of thefirst and second attachment members 300, 310 will be positioned adjacentto in operative contact with the inner or interior surface 89 b of thetrack 88, and the second sections 304, 314 of the first and secondattachment members 300, 310 will be positioned adjacent to or inoperative contact with one edge of the track 88. With the cleat 278 thuspositioned, the cleat may be secured to the track 88 with the thirdattachment member 320, whose extension 326 will also be positionedadjacent the inner or interior surface 89 b of the track 88, and whoseside wall 322 will be positioned adjacent the opposite edge of the track88. Note that the third sections 306, 316 of the first and secondattachment members 300, 310, and the extension 326 of the thirdattachment member 320 are configured and arranged so as to avoidinterfering with projections 326, 328 of the inner or interior surface89 b of track 88. Removal of the cleat 278 is achieved by reversing theforegoing steps.

An alternative, preferred embodiment of an endless, flexible track isshown in FIGS. 20-23. This embodiment comprises an endless, flexibletrack 400 that comprises a band with side edges, an inner or interiorsurface 402 and an outer or exterior surface 404, with the inner surfaceincluding two rows of inwardly extending projections 406, 408. As withendless track 88, the inwardly extending projections 406 are centrallylocated and are configured and arranged to be engaged by a drivesprocket 86 and to pass between the paired idler 74, 76 and bogey 80,82, 84 wheels. The inwardly extending projections 408 are primarily usedto guide the track 400 about the idler 74, 76 and bogey 80, 82, 84wheels of the track assembly unit 62. The exterior surface 404 differsfrom the exterior surface 89 a of flexible track 88 in that it is notpopulated with a plurality of lands or treads that define thin channelsor grooves therebetween. Instead, the exterior surface 404 of flexibletrack 400 includes a plurality of panels 410 that are separated by lugsor bars 412. As shown, each panel 410 has a preferred width “W” of about15 inches (38 cm), which is around the preferred width “W” of flexibletrack 88, 400, and a preferred length 414 of about 11-12 inches (27-31cm). Each lug or bar 412 preferably extends transversely across thewidth of the track 400 from side to side, and has a preferred height 416of about 1.45 inches (3.7 cm) and a base thickness 418 of about 1.50inches (3.8 cm). With a flexible track 400 having an inner periphery orpitch length of around 166 inches (421 cm), there are preferably aboutten panels 410 and ten lugs or bars 412 that are spaced evenly about theexterior surface 404 in an alternating fashion. The spacing 414 betweenthe lugs or bars 412 is critical to the operation of the track assemblyunit. It has been discovered that when the lugs or bars 412 are spacedrelatively far apart the soil, upon which the track assembly traverses,does not become sheared off or broken away. This is important becausewhen soil is sheared off or broken away, it becomes susceptible towash-out. This wash-out or breaking away of the soil is minimized whenthe lugs or bars 412 are spaced apart from each other, and traction isoptimized. Preferably, the panels and bars are arranged so that about3-4 bars are always be in simultaneous contact with the ground overwhich it travels.

It is to be understood that even though numerous characteristics andadvantages of various embodiments of the present invention have been setforth in the foregoing description, together with details of thestructure and function of various embodiments of the invention, thisdisclosure is illustrative only, and changes may be made in detail,especially in matters of structure and arrangement of parts within theprinciples of the present invention to the full extent indicated by thebroad general meaning of the terms in which the appended claims areexpressed.

What is claimed is:
 1. A track assembly suitable for use with aself-propelled irrigation vehicle having a plurality of tires, with eachtire removably connectable to a wheel hub, the track assemblycomprising: an adaptor comprising a body having a spindle, with the bodyconfigured and arranged to be attached to one of the wheel hubs; acarriage having a hub support frame with a spindle receiving aperture, afirst wheel support frame and a second wheel support frame; a sprocket;and, a plurality of wheels; wherein the plurality of wheels arerotatably mounted to the first and second wheel support frames; whereinthe sprocket is removably attached to the adaptor; wherein the spindleof the adaptor is rotatably mounted in the spindle receiving aperture ofthe hub support frame; and wherein a portion of one of the first orsecond wheel support frames is located directly beneath the sprocket;and an endless track having an inner surface and an outer surface, thetrack installed about the carriage so that an inner surface is able tocontact the plurality of wheels and the sprocket, wherein the sprocketis able to drivingly engage the endless track.
 2. The track assembly ofclaim 1, wherein the sprocket comprises a plurality of segments.
 3. Thetrack assembly of claim 1, wherein the sprocket is a split sprocket. 4.The track assembly of claim 1, wherein at least two of the plurality ofwheels comprise idler wheels, with the idler wheels are located atopposite ends of the carriage and with the idler wheels defining awheelbase, and wherein at least one of the idler wheels is adjustablypositionable relative to the other idler wheel, whereby the length ofthe wheelbase may be varied.
 5. The track assembly of claim 1, whereinthe first wheel support frame and second wheel support frame areslidingly and adjustably movable relative to each other.
 6. The trackassembly of claim 1, wherein a portion of one of the first or secondwheel support frames is telescopically received by a portion of theother of the first or second wheel support frames.
 7. The track assemblyof claim 1, wherein the carriage further comprises a tensioningapparatus that is operatively connected to the first wheel support frameand second wheel support frame, wherein the tensioning apparatus isconfigured and arranged to be able to urge the first and second wheelsupport frames away from each other along a general longitudinal axis ofthe carriage.
 8. The track assembly of claim 7, wherein the tensioningapparatus is selected from the group consisting of a grease cylinder anda hydraulic cylinder.
 9. The track assembly of claim 1, wherein theendless track includes at least one cleat having a ground engagingmember with a working surface, wherein the cleat is able to bepositioned over an outer transverse portion and opposing side edges ofthe endless track and removably attached thereto; wherein, in operation,the working surface of the cleat is able to project outwardly beyond theouter surface of the endless track.
 10. The track assembly of claim 9,wherein the cleat includes a plurality of attachment members that areconfigured and arranged to contact the inner surface of the endlesstrack when the cleat is operatively attached to the endless track. 11.The track assembly of claim 10, wherein one of the attachment members isconfigured to be removably connected to the cleat.
 12. The trackassembly of claim 1, wherein the first wheel support frame includes atop plate with an upper surface and opposing sides, the top plateforming a generally U-shaped recess, wherein one side of the U-shapedrecess is substantially bounded by the hub support frame, wherein theother side of the U-shaped recess is substantially unbounded, whereinthe unbounded side allows the sprocket to be installed or removed in adirection parallel to the rotational axis of the adaptor.
 13. The trackassembly of claim 1, wherein the body of the adaptor comprises a flangeto which the sprocket segments may be removably secured.
 14. The trackassembly of claim 1, wherein the body of the adaptor comprises a ringextension that is configured and arranged to be attached to a wheel hub.15. A self-propelled irrigation vehicle comprising: a plurality of wheelhubs operatively connected to at least one motive source, with the wheelhubs operatively connected to a structure that supports a water conduit;and a plurality of track assemblies, each track assembly including: anadaptor having a body and a spindle, with the adaptor configured andarranged to be removably attached to one of the plurality of wheel hubs;a carriage having a hub support frame with a spindle receiving aperture,a first wheel support frame and a second wheel support frame; asprocket, and a plurality of wheels; wherein the plurality of wheels arerotatably mounted on the first and second wheel support frames; whereinthe sprocket comprises a plurality of segments, each of which isremovably attachable to the body of the adaptor; wherein the spindle ofthe adaptor is rotatably mounted in the spindle receiving aperture ofthe hub support frame; and wherein a portion of one of the first orsecond wheel support frames is located directly beneath the sprocket;and a flexible, endless track installed about the carriage so that aninner surface of the endless track is able to contact the plurality ofwheels and the sprocket, and wherein the sprocket drivingly engages theendless track.
 16. The self-propelled irrigation vehicle of claim 15,wherein the sprocket comprises two arcuately-shaped segments.
 17. Theself-propelled irrigation vehicle of claim 15, wherein at least two ofthe plurality of wheels define a wheelbase, and wherein at least one ofthe plurality of wheels that define the wheelbase is adjustablypositionable relative to the other of the plurality of wheels thatdefine said wheelbase.
 18. The self-propelled irrigation vehicle ofclaim 15, wherein the first wheel support frame and the second wheelsupport frame are slidingly and adjustably movable relative to eachother.
 19. The self-propelled irrigation vehicle of claim 15, whereinthe carriage further comprises a tensioning apparatus that isoperatively connected to the first wheel support frame and second wheelsupport frame, wherein the tensioning apparatus is configured andarranged to be able to urge the first and second wheel support framesaway from each other along a general longitudinal axis of the carriage.20. The self-propelled irrigation vehicle of claim 19, wherein thetensioning apparatus is selected from the group consisting of a greasecylinder and a hydraulic cylinder.
 21. The self-propelled irrigationvehicle of claim 15, wherein the flexible, endless track includes atleast one cleat having a ground engaging member with a working surface,wherein the cleat is able to be positioned on an outer transverseportion and around opposing side edges of the flexible, endless trackand removably attached thereto; wherein, in operation, the workingsurface of the cleat is able to project outwardly beyond the outersurface of the flexible, endless track.
 22. The self-propelledirrigation vehicle of claim 21, wherein the cleat includes a pluralityof attachment members that are configured and arranged to contact theinner surface of the flexible, endless track when the cleat is attachedto the flexible endless track.
 23. The self-propelled irrigation vehicleof claim 21, wherein a section of the cleat is configured and arrangedto be engagably received within a substantially transverse channel onthe exterior surface of the flexible, endless track.
 24. Theself-propelled irrigation vehicle of claim 15, wherein the first wheelsupport frame includes a top plate forming a generally U-shaped recess,wherein one side of the U-shaped recess is substantially bounded by thehub support frame, wherein the other side of the U-shaped recess issubstantially unbounded, wherein the unbounded side allows the sprocketto be installed or removed in a direction parallel to the rotationalaxis of the adaptor.
 25. The self-propelled irrigation vehicle of claim15, wherein the body of the adaptor comprises a flange to which thesprocket segments may be removably secured.
 26. The self-propelledirrigation vehicle of claim 15, wherein there are two wheel hubs and thewheel hubs are operatively connected to at least one motive source. 27.A method of converting a self-propelled, tire supported irrigationvehicle to a self-propelled, track supported irrigation vehicle, themethod comprising the steps of: a.) providing a self-propelledirrigation vehicle having a plurality of powered hubs with each hubhaving a support tire removably connected thereto; b.) providing aplurality of track assemblies, each track assembly including an adaptorcomprising a body and a spindle, with the adaptor configured andarranged to be attached to one of the hubs of the irrigation vehicle, acarriage having a hub support frame with a spindle receiving aperture, afirst wheel support frame and a second wheel support frame; a sprocket,with a portion of the sprocket located directly above one of the firstor second wheel support frames, a plurality of bogey wheels and aplurality of idler wheels, with the plurality of idler and bogey wheelsrotatably mounted on only the first and second wheel support frames; andan endless track having an inner surface and an outer surface, theendless track installed about the carriage so that the inner surface ofthe endless track is able to contact the plurality of bogey wheels, theplurality of idler wheels and the sprocket, and wherein the sprocket isable to drivingly engage the endless track; c.) removing one of theplurality of support tires from the respective hub; d.) securing theadaptor to the respective hub; e.) attaching the sprocket to theadaptor; f.) attaching the carriage to the spindle; and g.) positioningthe endless belt about the sprocket and wheels.
 28. The method of claim27, wherein steps e and f are reversed.
 29. The method of claim 27,wherein the self-propelled irrigation vehicle provided includes twohubs, wherein the hubs are operatively connected to at least one motivesource.
 30. The method of claim 27, further comprising the steps of: h.)providing at least one cleat comprising a ground engaging member and anattachment member; and i.) removably attaching the cleat to the endlesstrack such that the ground engaging member of the cleat extendsoutwardly from the outer surface of the endless track.
 31. The method ofclaim 30, wherein the cleat includes a plurality of attachment members,wherein each attachment member contacts the inner surface of the endlesstrack when the cleat is attached to the endless track.
 32. The method ofclaim 31, wherein one of the attachment members is removably connectableto one end of the cleat, and wherein the step of removably attaching thecleat to the endless track includes the steps of: i) disconnecting theattachment member from the cleat; ii) positioning the cleat so that itsground engaging member is located on the outer surface of the endlesstrack and one of the attachment members is located adjacent the innersurface of the endless track; and iii) connecting the removableattachment member to the cleat such that the cleat secured to theendless track.
 33. The track assembly of claim 1, wherein at least oneof the first or second wheel support frames includes an upwardlyextending end portion.
 34. The self-propelled irrigation vehicle ofclaim 15, wherein at least one of the first or second wheel supportframes includes an upwardly extending end portion.
 35. A track assemblysuitable for use with a self-propelled irrigation vehicle having aplurality of tires, with each tire removably connectable to a wheel hub,the track assembly comprising: an adaptor comprising a body having aspindle, with the body configured and arranged to be attached to one ofthe wheel hubs; a carriage having a hub support frame with a spindlereceiving aperture, a first wheel support frame and a second wheelsupport frame; a segmented sprocket; a plurality of idler wheels, and atleast one bogey wheel; wherein a portion of one of the first or secondwheel support frames is telescopically received by a portion of theother of the first or second wheel support frames and adjustablerelative thereto; wherein the plurality of idler and bogey wheels arerotatably mounted to the first and second wheel support frames; whereineach segment of the sprocket is removably attachable to the adaptor;wherein the spindle of the adaptor is rotatably mounted in the spindlereceiving aperture of the hub support frame; and wherein a portion ofone of the first or second wheel support frames is located directlybeneath the sprocket; and an endless track having an inner surface andan outer surface, the track installed about the carriage so that aninner surface is able to contact the plurality of wheels and thesprocket, wherein the sprocket is able to drivingly engage the endlesstrack.